Roll up flexible doors are well known. Typical roll up flexible doors have a flexible material that is mounted upon a shaft to allow the material to be rolled upon and unrolled from the shaft. Some of these doors include tracks mounted on the sides of the opening to guide and hold the flexible material in place.
One of the problems with known doors is the lack of a tight fit across the opening. Even with track mounted doors, the doors can have a lose fit, particularly after repeated use. This can create numerous disadvantages, such as unsightly appearance and reduced thermal barrier.
Another problem with flexible doors that are mounted in tracks is when the door is inadvertently hit by for example a fork lift. Typical doors are damaged and require replacement. Either the flexible door has to be reinstalled or replaced, or in more severe situations, the tracks have to be replaced.
It is desirable to provide a flexible door that tightens laterally as it is lowered to eliminate the problems associated with loose doors. Additionally, it is desirable to provide a flexible door that is resistant to damage and easily reinstalled if inadvertently hit during use.